Stretching our grey matter this week is developmental biologist Dr Adrian Pini, who describes how our brain grows, how our brain works, and how it can become damaged, and Dr Huseyin Mehmet, who discusses the potential application of stem cells in repairing central nervous system damage. Also in the studio is Tom Smith from Cambridge University, who has designed a new pump that could help thousands of people in the developing world, and Derek and Dave perform a vanishing act in Kitchen Science. Like this podcast? Please help us by supporting the Naked Scientists